A group of copper carrying compounds and PGE1 were found to induce new formation of capillaries in the corneal assay. Neoplastic tissue as well as the chemically defined angiogenesis effectors stimulate in the cornea the production of a chemoattractant for the capillary endothelium. The chemoattractant was extracted, isolated by gel filtration chromatography, purified about 200X and shown to be identical regardless of the angiogenesis effector used to stimulate the cornea. The chemotactic activity appears to be exclusively directed toward the capillary endothelium and probably consists of two components that must be combined for optimal mobilization effect.